There is a WW Synopsis and Outline Group where you can upload your synopsis for review, MissScarlett, and there are threads on there with pointers on how to write a synopsis, although it is difficult to generalize on such things, since synopsises are like patent leather shoes - made to fit the person, aka the story.
As a broad rule of thumb, one page is good; two pages if it is particularly complex. Avoid getting bogged down in sub-plots and minor characters. Last but not least, include the ending, and don't skimp on the ending.
Good luck,
NaomiM
<Added>here's thee link:
http://www.writewords.org.uk/groups/80.asp#forum